Compressor

ABSTRACT

Provided is a compressor which enables reliable separation of oil from a refrigerant gas while suppressing increases in the size of equipment and manufacturing costs. Provided is a compressor ( 1 ) including a housing ( 2 ), a compression mechanism ( 13 ) compressing a refrigerant gas flowing into a suction space (Ss), an oil separation space (So) separating oil from the refrigerant gas compressed by the compression mechanism ( 13 ) and guiding the refrigerant gas to a discharge pipe ( 40 ), and a separation cylinder ( 30 ) disposed along an axis line (X 2 ) of the oil separation space (So) above the oil separation space (So) in a gravitational direction. The separation cylinder ( 30 ) has a small-diameter section, a large-diameter section formed below the small-diameter section in the gravitational direction, and an introduction inlet formed in the small-diameter section. The oil separation space (So) has a separation section in which the small-diameter section and the large-diameter section are disposed, the separation section having a first inner diameter larger than a second outer diameter of the large-diameter section, and an oil storage section disposed below the separation section. The refrigerant gas compressed by the compression mechanism ( 13 ) flows into the separation section.

TECHNICAL FIELD

The present invention relates to a compressor.

BACKGROUND ART

Known in the related art is an oil separation mechanism being providedin a compressor of an automotive air conditioner or the like so that alubricant contained in a refrigerant is discharged only to thecompressor (see, for example, PTL 1 and 2).

PTL 1 discloses separating a lubricant by causing a refrigerant guidedto a separation chamber 11 to orbit in a cylindrical space in which aseparation pipe 12a is disposed and discharging the separated lubricantto an oil storage chamber 15.

PTL 2 discloses forming an oil separation chamber 20 and an oilreservoir 25 as one space and guiding an oil-separated refrigerant gasto an internal space 33 from a small hole 32 formed in a small-diametersection 29 of an oil separation cylinder 26.

CITATION LIST Patent Literature [PTL 1] Japanese Unexamined PatentApplication Publication No. 2001-295767

[PTL 2] Japanese Unexamined Patent Application Publication No.2014-20306

SUMMARY OF INVENTION Technical Problem

The mechanism that is disclosed in PTL 1 is a mechanism in which the oilstorage chamber 15 storing the separated lubricant is providedseparately from the separation chamber 11 in which the lubricant isseparated from the refrigerant.

Accordingly, a sufficient space is required for two spaces to beprovided and an increase in the size of the compressor cannot besuppressed.

In addition, an increase in manufacturing costs arises from the complexshape in which the two spaces are provided.

In the mechanism that is disclosed in PTL 2, the oil separation chamber20 and the oil reservoir 25 are formed as one space, and thus thecompressor can be reduced in size.

In the mechanism that is disclosed in PTL 1, however, the small-diametersection 29 is formed on the oil reservoir 25 side below the oilseparation cylinder 26 and the small hole 32 guiding the refrigerant tothe internal space 33 is formed in the small-diameter section 29.

Accordingly, the oil may be wound up from the oil reservoir 25 below theoil separation cylinder 26 by the orbiting flow of the refrigerant gas,the oil may be drawn from the small hole 32 into the internal space 33,and then the oil separation from the refrigerant gas may becomeinsufficient.

The present invention has been made in view of such circumstances, andan object of the present invention is to provide a compressor whichenables reliable separation of oil from a refrigerant gas whilesuppressing increases in the size of equipment and manufacturing costs.

Solution to Problem

In order to solve the above problems, a compressor of the presentinvention adopts the following means.

A compressor according to an aspect of the present invention includes ahousing forming a suction space for a refrigerant gas inside, acompression mechanism disposed in the housing and compressing therefrigerant gas flowing into the suction space, an oil separation spaceformed in the housing so as to extend in a gravitational direction,separating oil from the refrigerant gas compressed by the compressionmechanism, and guiding the refrigerant gas to a discharge pipe, and acylindrical member disposed along an axis line of the oil separationspace above the oil separation space in the gravitational direction. Thecylindrical member has a small-diameter section having a first outerdiameter, a large-diameter section formed below the small-diametersection in the gravitational direction and having a second outerdiameter larger than the first outer diameter, and an introduction inletguiding the refrigerant gas from a lower end of the small-diametersection to an internal space of the cylindrical member. The oilseparation space has a first space section in which the small-diametersection and the large-diameter section are disposed, the first spacesection having a first inner diameter larger than the second outerdiameter, and a second space section disposed below the first spacesection in the gravitational direction. The refrigerant gas compressedby the compression mechanism flows into the first space section.

In the compressor of this aspect, the refrigerant gas compressed by thecompression mechanism flows into the first space section and orbitsaround the axis line in the space between the outer peripheral surfaceof the cylindrical member and the inner peripheral surface of the firstspace section.

The oil contained in the refrigerant gas is separated from therefrigerant gas by the centrifugal force acting during the orbiting,adheres to the inner peripheral surface of the first space, and isguided along the inner peripheral surface to the inner peripheralsurface of the second space disposed below in the gravitationaldirection.

The oil guided to the inner peripheral surface of the second space ismoved downward by gravity and forms an oil reservoir below the secondspace.

After the oil separation in the first space section, the refrigerant gasis guided to the internal space of the cylindrical member from theintroduction inlet formed in the small-diameter section of thecylindrical member and is further guided to the discharge pipe.

The large-diameter section larger in outer diameter than thesmall-diameter section is formed below the small-diameter section of thecylindrical member.

Accordingly, in a case where the refrigerant gas orbiting in the firstspace section reaches the lower end of the small-diameter section, therefrigerant gas being guided in quantity to the second space below thelarge-diameter section is suppressed since the interval between theinner peripheral surface of the first space section and the outerperipheral surface of the large-diameter section is small.

Accordingly, a large amount of the refrigerant gas winding up the oilreservoir below the second space section is suppressed.

In this manner, with the compressor of this aspect, it is possible toseparate oil from a refrigerant gas in the first space section above theoil separation space and form the oil reservoir in the second spacesection below the first space section.

It is not necessary to separately provide a space for oil separation anda space for an oil reservoir, and thus increases in the size ofequipment and manufacturing costs can be suppressed.

In addition, the orbiting flow of the refrigerant gas being guided inquantity from the first space section to the second space section andthe oil reservoir being wound up can be suppressed, and thus oilseparation from the refrigerant gas can be performed with reliability.

In the compressor according to an aspect of the present invention, thelarge-diameter section may be formed in a tapered shape having an outerdiameter gradually increasing from the first outer diameter to thesecond outer diameter from an upper side toward a lower side in thegravitational direction.

As a result, it is possible to appropriately prevent the refrigerant gasfrom being guided to the second space section while circulating theorbiting flow of the refrigerant gas guided to the large-diametersection without disturbing the orbiting flow.

In the compressor according to an aspect of the present invention, therefrigerant gas compressed by the compression mechanism may flow in froman upper part of the small-diameter section and the introduction inletmay be formed at a lower end of the small-diameter section in thegravitational direction.

As a result, it is possible to form the orbiting flow of the refrigerantgas in a wide range from the upper side to the lower side of the firstspace section and oil can be appropriately separated from therefrigerant gas.

In the compressor according to an aspect of the present invention, thecompression mechanism may be a mechanism compressing the refrigerant gasby a pair of a fixed scroll and an orbiting scroll being disposed so asto face each other and the orbiting scroll being driven to revolve withrespect to the fixed scroll.

As a result, in the scroll compressor, oil separation from therefrigerant gas can be performed with reliability with increases in thesize of equipment and manufacturing costs suppressed.

Advantageous Effects of Invention

According to the present invention, it is possible to provide acompressor which enables reliable separation of oil from a refrigerantgas while suppressing increases in the size of equipment andmanufacturing costs.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a longitudinal cross-sectional view of a scroll compressoraccording to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the scroll compressor illustrated inFIG. 1 taken along the A-A arrow.

FIG. 3 is a partially enlarged view of an oil separation space part of arear housing illustrated in FIG. 1.

FIG. 4 is a partially enlarged view illustrating a modification exampleof the oil separation space part of the rear housing illustrated in FIG.3.

FIG. 5 is a side view of the rear housing illustrated in FIG. 1 asviewed from a compression mechanism side.

DESCRIPTION OF EMBODIMENTS

Hereinafter, an embodiment of a compressor according to the presentinvention will be described with reference to accompanying drawings.

Illustrated in FIG. 1 is a longitudinal cross-sectional view of a scrollcompressor according to an embodiment of the present invention.Illustrated in FIG. 2 is a cross-sectional view taken along the A-Aarrow in FIG. 1.

As illustrated in FIG. 1, a scroll compressor 1 of the presentembodiment is provided with a cylindrical housing 2 constituting anouter shell, a compression mechanism 13 accommodated in the housing 2,an oil separation space So formed in the housing 2, and a separationcylinder (cylindrical member) 30 disposed above the oil separation spaceSo.

The housing 2 has a front housing 3 and a rear housing 4.

The front housing 3 and the rear housing 4 are fastened by a fasteningbolt (not illustrated) such that a refrigerant gas suction space Ss isformed inside.

On the front housing 3 side in the housing 2, a crankshaft 5 issupported so as to be rotatable around an axis line X1 via a mainbearing 6 and a sub bearing (not illustrated).

One end side (left side in FIG. 1) of the crankshaft 5 penetrates thefront housing 3 and protrudes to the left side in FIG. 1. Anelectromagnetic clutch 7 and a pulley 8 are provided at the protrudingpart.

Power is input to the pulley 8 from a driving source such as an enginevia a driving belt (not illustrated).

A mechanical seal or a lip seal is installed between the main bearing 6and the sub bearing. As a result, sealing is provided between the insideof the housing 2 and the atmosphere.

A crank pin 9 is integrally provided on the other end side (right sidein FIG. 1) of the crankshaft 5. The crank pin 9 has a central axis lineeccentric by a predetermined dimension with respect to the axis line X1.

The crank pin 9 is connected to an orbiting scroll (described later) viaa drive bush 10 and a drive bearing 11.

The orbiting scroll 15 orbits around the axis line X1 by the drivingforce with which the crankshaft 5 rotates around the axis line X1 beingtransmitted via the crank pin 9.

A balance weight 12 for removing the unbalance load generated by theorbiting scroll 15 orbiting around the axis line X1 is integrally formedon the drive bush 10.

The balance weight 12 orbits around the axis line X1 together with theorbiting scroll 15.

A driven crank mechanism (not illustrated) making the turning radius ofthe orbiting scroll 15 variable is provided between the drive bush 10and the crank pin 9.

The compression mechanism 13 constituted by a pair of a fixed scroll 14and the orbiting scroll 15 is incorporated in the housing 2.

The compression mechanism 13 is a mechanism compressing a refrigerantgas flowing into the suction space Ss and discharging the compressedrefrigerant gas to a discharge space Sd.

An end plate 14A and a scroll-shaped wrap 14B erected from the end plate14A constitute the fixed scroll 14.

An end plate 15A and a scroll-shaped wrap 15B erected from the end plate15A constitute the orbiting scroll 15.

As illustrated in FIG. 2, the fixed scroll 14 and the orbiting scroll 15are configured to be provided with step sections 14C and 15C and 14D and15D at predetermined positions along the scroll directions of the toothcrests and the bottom lands of the scroll-shaped wraps 14B and 15B.

The tooth crest on the outer peripheral side in the orbiting axis linedirection is high and the tooth crest on the inner peripheral side inthe orbiting axis line direction is low on the tooth crest side with thestep sections 14C and 15C and 14D and 15D as boundaries.

On the bottom land side, the bottom land on the outer peripheral side inthe orbiting axis line direction is low and the bottom land on the innerperipheral side in the orbiting axis line direction is high.

As a result, in the scroll-shaped wraps 14B and 15B, the wrap height onthe outer peripheral side is higher than the wrap height on the innerperipheral side.

The fixed scroll 14 and the orbiting scroll 15 are disposed in a statewhere the central axes of each other are shifted by the distance of theturning radius of the orbiting scroll 15 and the scroll-shaped wraps 14Band 15B face each other.

In addition, the fixed scroll 14 and the orbiting scroll 15 areassembled such that the scroll-shaped wraps 14B and 15B are meshed 180degrees out of phase and there is a slight clearance (tens to hundredsof microns) at room temperature between the tooth crest and the bottomland of the scroll-shaped wraps 14B and 15B.

As a result, a pair of suction volumes (compression chambers) 16 formedby the end plates 14A and 15A and the scroll-shaped wraps 14B and 15Bbetween the fixed scroll and the orbiting scroll 15 are formed with aphase difference of 180 degrees with respect to the central axis line.

In the suction volume 16, the heights of the scroll-shaped wraps 14B and15B are higher on the outer peripheral side than on the inner peripheralside. The suction volume 16 constitutes the compression mechanism 13capable of performing three-dimensional compression for compressing arefrigerant gas in both the circumferential direction and the heightdirection of the scroll-shaped wraps 14B and 15B.

The compression mechanism 13 is provided with the step sections 14C and15C and 14D and 15D. The compression mechanism 13 may be a compressionmechanism having no step section.

The fixed scroll 14 is fixed to the inner surface of the rear housing 4via a fastening bolt (not illustrated).

In the orbiting scroll 15, the crank pin 9 provided on one end side ofthe crankshaft 5 is connected via the drive bush 10 and the drivebearing 11 to the bearing boss part provided on the back surface of theend plate 15A.

With the back surface of the end plate 15A supported by a thrust bearingsurface 3A of the front housing 3, the orbiting scroll 15 is driven torevolve around the fixed scroll 14 while rotation is prevented via arotation prevention mechanism (not illustrated) provided between thethrust bearing surface 3A and the back surface of the end plate 15A.

In the fixed scroll 14, a discharge port 17 is formed at a central partof the end plate 14A. A refrigerant gas compressed by the compressionmechanism 13 is discharged through the discharge port 17.

A discharge reed valve 19 is installed via a retainer 18 at thedischarge port 17.

A seal member (not illustrated) is disposed between the back surface onthe outer peripheral side of the end plate 14A of the fixed scroll 14and the inner surface of the rear housing 4.

The discharge space Sd partitioned from the suction space Ss of thehousing 2 is formed between the back surface of the end plate 14A andthe inner surface of the rear housing 4.

A high-temperature and high-pressure refrigerant gas compressed by thecompression mechanism 13 is discharged to the discharge space Sd via thedischarge port 17.

The suction space Ss in the housing 2 communicates with a suction port20 provided in the upper portion of the front housing 3.

A low-temperature and low-pressure refrigerant gas is supplied to thesuction port 20 from a refrigeration cycle side.

The low-temperature and low-pressure refrigerant gas supplied to thesuction space Ss is compressed after being suctioned into the twosuction volumes (compression chambers) 16 formed with a phase differenceof 180 degrees with respect to the fixed scroll 14 by the orbitingscroll 15 being driven to orbit.

As illustrated in FIGS. 1 and 2, the low-temperature refrigerant gassuctioned into the suction space Ss from the suction port 20 issuctioned into the suction volume (compression chamber) 16 on the sidethat is close to the suction port 20 as indicated by arrow a.

The low-temperature refrigerant gas suctioned into the suction space Ssfrom the suction port 20 is suctioned into the suction volume(compression chamber) 16 on the side that is far from the suction port20 as indicated by arrow b.

The refrigerant gas suctioned into the suction volume 16 is compressedand guided from the discharge port 17 to the discharge space Sd.

Next, a mechanism for separating oil from the refrigerant gas compressedby the compression mechanism 13 and guided to the discharge space Sd andguiding the oil-separated refrigerant gas to a discharge pipe 40 will bedescribed.

This mechanism is a mechanism for separating the refrigerant gas flowingfrom the discharge space Sd into the oil separation space So in the oilseparation space So by means of the separation cylinder 30.

Hereinafter, the mechanism will be described with reference to FIGS. 1,3, and 4.

FIG. 3 is a partially enlarged view of the oil separation space So partof the rear housing 4 illustrated in FIG. 1.

FIG. 4 is a side view of the rear housing 4 illustrated in FIG. 1 asviewed from the compression mechanism 13 side.

As illustrated in FIG. 1, the oil separation space So for oil separationfrom the refrigerant gas compressed by the compression mechanism 13 andguiding to the discharge pipe 40 is formed in the rear housing 4.

The oil separation space So is a space having a circular cross-sectionalview in the horizontal direction and is formed along an axis line X2extending in the vertical direction.

As illustrated in FIG. 3, which is a partially enlarged view, thediameter of the horizontal cross section of the oil separation space Sois a first inner diameter Di1 constant at any vertical position.

Accordingly, the oil separation space So can be formed by a relativelysimple work in which a hole having the constant first inner diameter Di1is drilled along the axis line X2 after the rear housing 4 ismanufactured by casting.

As illustrated in FIGS. 1 and 3, in the oil separation space So, theseparation cylinder 30 is disposed along an axis line X2 extending inthe vertical direction.

The separation cylinder 30 is a cylindrical member formed so as to havecircular outer and inner diameters in a horizontal cross section.

As illustrated in FIG. 3, the separation cylinder 30 has asmall-diameter section 31 having a first outer diameter Do1, alarge-diameter section 32 formed below the small-diameter section 31 andhaving a second outer diameter Do2 larger than the first outer diameterDo1, an introduction inlet 33 formed in the small-diameter section 31and guiding a refrigerant gas to an internal space Si of the separationcylinder 30, and a flange section 34 sealing the upper end opening ofthe oil separation space So.

As illustrated in FIG. 3, the large-diameter section is formed in atapered shape in which the outer diameter gradually increases from thefirst outer diameter Do1 to the second outer diameter Do2 from the upperside toward the lower side in the vertical direction.

The introduction inlet 33 is formed at a plurality of locations aroundthe axis line X2 (such as two locations spaced 180 degrees around theaxis line X2 and four locations spaced 90 degrees around the axis lineX2).

As illustrated in FIG. 3, the flange section 34 is provided with arecess 34 a into which a tip portion 40 a of the discharge pipe 40transporting the refrigerant gas guided from the internal space Si ofthe separation cylinder 30 is inserted.

As illustrated in FIG. 1, a through-hole 34 b is formed in the flangesection 34 and a through-hole 41 is formed in the discharge pipe 40.

A fastening hole 21 is formed in the rear housing 4. The discharge pipe40 and the flange section 34 of the separation cylinder 30 are fixed tothe rear housing 4 by a fastening bolt (not illustrated) inserted in thethrough-hole 34 b and the through-hole 41 being fastened to thefastening hole 21.

In the scroll compressor 1 of the present embodiment, the tip portion 40a of the discharge pipe 40 is inserted into the recess 34 a formed inthe flange section 34 of the separation cylinder 30 inserted in the oilseparation space So without being directly inserted into the oilseparation space So.

Accordingly, it is possible to increase the inner diameter of the oilseparation space So without, for example, changing the shape of the tipportion 40 a of the discharge pipe 40.

For example, as in the modification example that is illustrated in FIG.4, it is possible to increase the inner diameter of the oil separationspace So to a second inner diameter Di2 larger than the first innerdiameter Di1 illustrated in FIG. 3 without changing the shape of the tipportion 40 a of the discharge pipe 40.

By increasing the inner diameter of the oil separation space So, it ispossible to increase an oil-separating centrifugal force in forming anorbiting flow Fs of a refrigerant gas (described later) and improve theoil separation performance.

In FIG. 4, the shapes of a recess 34Aa and a flange section 34A of aseparation cylinder 30A are set in accordance with the second innerdiameter Di2 of the oil separation space So, and thus the inner diameterof the oil separation space So is increased without a change in theshape of the tip portion 40 a of the discharge pipe 40.

As illustrated in FIG. 3, the oil separation space So has a separationsection (first space section) So1 in which the small-diameter section 31and the large-diameter section 32 are disposed and an oil storagesection (second space section) So2 disposed below the separation sectionSo1 in the vertical direction.

As illustrated in FIG. 3, the first inner diameter Di1 of the separationsection So1 is larger than the second outer diameter Do2 of thelarge-diameter section 32.

Here, how oil is separated from a refrigerant gas in the oil separationspace So in which the separation cylinder 30 is disposed will bedescribed.

A refrigerant gas compressed by the compression mechanism 13 and guidedto the discharge space Sd flows from two inflow ports 22 into the upperpart of the separation section So1 of the oil separation space So.

The small-diameter section 31 of the separation cylinder 30 is disposedin the separation section So1, and thus the separation section So1 has acylindrical space extending along the axis line X2.

Accordingly, the refrigerant gas flowing into the separation section So1from the inflow port 22 forms the orbiting flow Fs and is guided to theintroduction inlet 33 formed at the lower end of the small-diametersection 31 while orbiting around the axis line X2.

The oil contained in the refrigerant gas is separated from therefrigerant gas by the centrifugal force acting when the refrigerant gasbecomes the orbiting flow Fs and orbits in the separation section So1.

The oil separated from the refrigerant gas adheres to the innerperipheral surface of the separation section So1 and is guided along theinner peripheral surface to the inner peripheral surface of the oilstorage section So2 below.

The oil guided to the inner peripheral surface of the oil storagesection So2 is moved downward by gravity and forms an oil reservoir Osbelow the oil storage section So2.

As illustrated in FIG. 5, the position where the inflow port 22 causingthe refrigerant gas to flow into the oil separation space So from thedischarge space Sd is disposed is closer to the inner peripheral surfaceof the oil separation space So than to the axis line X2.

This is for the refrigerant gas that has flowed into the oil separationspace So to form the orbiting flow Fs orbiting around the axis line X2.

By the refrigerant gas being caused to flow along the inner peripheralsurface of the oil separation space So, the refrigerant gas becomes theorbiting flow Fs orbiting around the axis line X2.

Desirably, the value of the first inner diameter Di1 and the value ofthe second outer diameter Do2 are determined such that the value ofDo2/Di1 is 0.8 or more and 0.9 or less.

By setting the value of Do2/Di1 to 0.8 or more, it is possible to narrowthe gap between the outer peripheral surface of the large-diametersection 32 and the inner peripheral surface of the separation sectionSo1 and suppress the orbiting flow of the refrigerant gas flowing inquantity from the separation section So1 into the oil storage sectionSo2.

By setting the value of Do2/Di1 to 0.9 or less, it is possible to ensurea gap to a certain extent or more between the outer peripheral surfaceof the large-diameter section 32 and the inner peripheral surface of theseparation section So1 and promote the flow of the oil separated fromthe refrigerant gas from the separation section So1 to the oil storagesection So2.

The action and effect of the scroll compressor 1 of the presentembodiment described above will be described below.

In the scroll compressor 1 of the present embodiment, a refrigerant gascompressed by the compression mechanism 13 flows into the separationsection So1 and orbits around the axis line X2 along the verticaldirection in the space between the outer peripheral surface of theseparation cylinder 30 and the inner peripheral surface of theseparation section So1.

The oil contained in the refrigerant gas is separated from therefrigerant gas by the centrifugal force acting during the orbiting,adheres to the inner peripheral surface of the separation section So1,and is guided along the inner peripheral surface to the inner peripheralsurface of the oil storage section So2 below.

The oil guided to the inner peripheral surface of the oil storagesection So2 is moved downward by gravity and forms the oil reservoir Osbelow the oil storage section So2.

After the oil separation in the separation section So1, the refrigerantgas is guided to the internal space Si of the separation cylinder 30from the introduction inlet 33 formed in the small-diameter section 31of the separation cylinder 30 and is further guided to the dischargepipe 40.

The large-diameter section 32 larger in outer diameter than thesmall-diameter section 31 is formed below the small-diameter section 31of the separation cylinder 30.

Accordingly, in a case where the refrigerant gas orbiting in theseparation section So1 reaches the lower end of the small-diametersection 31, the refrigerant gas being guided to the oil storage sectionSo2 below the large-diameter section 32 is suppressed since the intervalbetween the inner peripheral surface of the separation section So1 andthe outer peripheral surface of the large-diameter section 32 is small.

Accordingly, winding up of the oil reservoir Os below the oil storagesection So2 is suppressed.

In this manner, with the scroll compressor 1 of the present embodiment,it is possible to separate oil from a refrigerant gas in the separationsection So1 above the oil separation space So and form the oil reservoirOs in the oil storage section So2 below the separation section So1.

It is not necessary to separately provide a space for oil separation anda space for an oil reservoir, and thus increases in the size ofequipment and manufacturing costs can be suppressed.

In addition, the orbiting flow Fs of the refrigerant gas being guided inquantity from the separation section So1 to the oil storage section So2and the oil reservoir being wound up can be suppressed, and thus oilseparation from the refrigerant gas can be performed with reliability.

In the scroll compressor 1 of the present embodiment, the large-diametersection 32 is formed in a tapered shape in which the outer diametergradually increases from the first outer diameter Do1 to the secondouter diameter Do2 from the upper side toward the lower side in thevertical direction.

As a result, it is possible to appropriately prevent the refrigerant gasfrom being guided to the oil storage section So2 while circulating theorbiting flow of the refrigerant gas guided to the large-diametersection 32 without disturbing the orbiting flow.

The shape of the large-diameter section 32 is not limited to the taperedshape. For example, the large-diameter section 32 may be formed in atubular shape having a constant second outer diameter Do2 along thevertical direction.

In the scroll compressor 1 of the present embodiment, the refrigerantgas compressed by the compression mechanism 13 flows in from the upperpart of the small-diameter section 31 and the introduction inlet 33 isformed at the lower end of the small-diameter section 31 in the verticaldirection.

As a result, it is possible to form the orbiting flow Fs of therefrigerant gas in a wide range from the upper side to the lower side ofthe separation section So1 and oil can be appropriately separated fromthe refrigerant gas.

Although a scroll compression mechanism is used as the compressionmechanism 13 in the present embodiment, another compression mechanismmay be used.

Although the axis line X2 extends in the vertical direction and the oilseparation space So and the separation cylinder 30 are disposed alongthe axis line X2 in the present embodiment, the present invention is notlimited thereto.

For example, the axis line X2 may be an axis line extending in adirection inclined by a predetermined angle (such as an angle of 13° ormore) from the horizontal direction.

In this case, the separation cylinder 30 is disposed along the axis lineX2 above the oil separation space So in the gravitational direction.

In addition, the large-diameter section 32 of the separation cylinder 30is formed below the small-diameter section 31 in the gravitationaldirection.

The oil contained in the refrigerant gas forms the oil reservoir Osbelow the oil storage section So2, even when the axis line X2 does notextend in the vertical direction, insofar as the axis line X2 extends ina direction inclined from the horizontal direction.

In other words, the oil contained in the refrigerant gas is separatedfrom the refrigerant gas by the centrifugal force acting during theorbiting, adheres to the inner peripheral surface of the separationsection So1, is guided along the inner peripheral surface to the innerperipheral surface of the oil storage section So2 below, and is moved bygravity to the lower part of the oil storage section So2.

REFERENCE SIGNS LIST

1 Scroll compressor

2 Housing

3 Front housing

4 Rear housing

5 Crankshaft

6 Main bearing

7 Electromagnetic clutch

8 Pulley

9 Crank pin

10 Drive bush

11 Drive bearing

12 Balance weight

13 Compression mechanism

14 Fixed scroll

15 Orbiting scroll

16 Suction volume

17 Discharge port

18 Retainer

19 Discharge reed valve

20 Suction port

21 Fastening hole

22 Inflow port

30 Separation cylinder (cylindrical member)

31 Small-diameter section

32 Large-diameter section

33 Introduction inlet

34 Flange section

40 Discharge pipe

Di1 First inner diameter

Do1 First outer diameter

Do2 Second outer diameter

Os Oil reservoir

Sd Discharge space

Si Internal space

So Oil separation space

So1 Separation section (first space section)

So2 Oil storage section (second space section)

Ss Suction space

X1, X2 Axis line

1. A compressor comprising: a housing forming a suction space for arefrigerant gas inside; a compression mechanism disposed in the housingand compressing the refrigerant gas flowing into the suction space; anoil separation space formed in the housing so as to extend in agravitational direction, separating oil from the refrigerant gascompressed by the compression mechanism, and guiding the refrigerant gasto a discharge pipe; and a cylindrical member disposed along an axisline of the oil separation space above the oil separation space in thegravitational direction, wherein the cylindrical member has asmall-diameter section having a first outer diameter, a large-diametersection formed below the small-diameter section in the gravitationaldirection and having a second outer diameter larger than the first outerdiameter, and an introduction inlet formed in the small-diameter sectionand guiding the refrigerant gas to an internal space of the cylindricalmember, the oil separation space has a first space section in which thesmall-diameter section and the large-diameter section are disposed, thefirst space section having a first inner diameter larger than the secondouter diameter, and a second space section disposed below the firstspace section in the gravitational direction, and the refrigerant gascompressed by the compression mechanism flows into the first spacesection.
 2. The compressor according to claim 1, wherein thelarge-diameter section is formed in a tapered shape having an outerdiameter gradually increasing from the first outer diameter to thesecond outer diameter from an upper side toward a lower side in thegravitational direction.
 3. The compressor according to claim 1, whereinthe refrigerant gas compressed by the compression mechanism flows infrom an upper part of the small-diameter section, and the introductioninlet is formed at a lower end of the small-diameter section in thegravitational direction.
 4. The compressor according to claim 1, whereinthe compression mechanism is a mechanism compressing the refrigerant gasby a pair of a fixed scroll and an orbiting scroll being disposed so asto face each other and the orbiting scroll being driven to revolve withrespect to the fixed scroll.